<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onBeforeMount, onBeforeUnmount, onMounted, ref } from 'vue';
// 定义props
const { slides, autoPlay=false, duration=3000 } = defineProps<{
  slides: BannerItem[],
  autoPlay?: boolean, // 是否开启自动播放
  duration?: number
}>()

// 当前哪个图片选中
const active = ref(0)

const hNext = () => {
  active.value++
  if(active.value === slides.length){
    active.value = 0
  }
}

const hPrev = () => {
  active.value--
  if(active.value < 0){
    active.value = slides.length - 1
  }
}

// 如果开启了自动播放，则每隔duration去播放下一张： hNext（）
onMounted(() => {
  start()
})

onBeforeUnmount(() => {
  stop()
})

let timer = -1 

// 鼠标离开要继续播放
const start = () => {
  if(autoPlay) {
    timer = window.setInterval(() => {
      hNext()
    }, duration)
  }
}
// 鼠标hover要暂停播放
const stop = () => {
  clearInterval(timer)
}
</script>

<template>
  <div class="xtx-carousel" @mouseleave="start()" @mouseenter="stop()">
    <ul class="carousel-body">
      <!-- fade类表示当前图片可见 -->
      <li class="carousel-item" :class="{fade: idx === active}" v-for="(item,idx) in slides" :key="item.id">
        <RouterLink to="/">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
      </li>
    </ul>
    <a @click="hPrev" href="javascript:;" class="carousel-btn prev"><i class="iconfont icon-angle-left"></i></a>
    <a @click="hNext" href="javascript:;" class="carousel-btn next"><i class="iconfont icon-angle-right"></i></a>
    
    <div class="carousel-indicator">
      <span
      v-for="(item,idx) in slides"
      @mouseover="active = idx"
      :class="{active: active===idx}"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>